/*
 * Copyright (C) 2011 Benoit GUEROUT <bguerout at gmail dot com> and Yves AMSELLEM <amsellem dot yves at gmail dot com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.kerbores.jongo;

import org.bson.LazyBSONObject;

import com.kerbores.jongo.query.Query;
import com.kerbores.jongo.query.QueryFactory;
import com.mongodb.BasicDBObject;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.WriteConcern;
import com.mongodb.WriteResult;

public class Update {

	private final DBCollection collection;
	private final Query query;
	private final QueryFactory queryFactory;

	private WriteConcern writeConcern;
	private boolean upsert = false;
	private boolean multi = false;

	Update(DBCollection collection, WriteConcern writeConcern, QueryFactory queryFactory, String query, Object... parameters) {
		this.collection = collection;
		this.writeConcern = writeConcern;
		this.queryFactory = queryFactory;
		this.query = createQuery(query, parameters);
	}

	public WriteResult with(String modifier) {
		return with(modifier, new Object[0]);
	}

	public WriteResult with(String modifier, Object... parameters) {
		Query updateQuery = queryFactory.createQuery(modifier, parameters);
		return collection.update(this.query.toDBObject(), updateQuery.toDBObject(), upsert, multi, writeConcern);
	}

	public WriteResult with(Object pojo) {

		DBObject updateDbo = queryFactory.createQuery("{$set:#}", pojo).toDBObject();
		removeIdField(updateDbo);
		return collection.update(this.query.toDBObject(), updateDbo, upsert, multi, writeConcern);
	}

	private void removeIdField(DBObject updateDbo) {
		DBObject pojoAsDbo = (DBObject) updateDbo.get("$set");
		if (pojoAsDbo.containsField("_id")) {
			// Need to materialize lazy objects which are read only
			if (pojoAsDbo instanceof LazyBSONObject) {
				BasicDBObject expanded = new BasicDBObject();
				expanded.putAll(pojoAsDbo);
				updateDbo.put("$set", expanded);
				pojoAsDbo = expanded;
			}
			pojoAsDbo.removeField("_id");
		}
	}

	public Update upsert() {
		this.upsert = true;
		return this;
	}

	public Update multi() {
		this.multi = true;
		return this;
	}

	private Query createQuery(String query, Object[] parameters) {
		try {
			return this.queryFactory.createQuery(query, parameters);
		} catch (Exception e) {
			String message = String.format("Unable execute update operation using query %s", query);
			throw new IllegalArgumentException(message, e);
		}
	}
}
